Re: [BUG? liburing] io_uring_register_files_update with liburing 2.0 on 5.13.17

[Jens Axboe <axboe@kernel.dk>]

On 9/19/21 5:56 AM, Pavel Begunkov wrote:
> On 9/18/21 11:21 PM, Jens Axboe wrote:
>> On 9/18/21 3:55 PM, Victor Stewart wrote:
>>>> BTW, this could be incorporated into io_uring_register_files and
>>>> io_uring_register_files_tags(), might not be a bad idea in general. Just
>>>> have it check rlim.rlim_cur for RLIMIT_NOFILE, and if it's smaller than
>>>> 'nr_files', then bump it. That'd hide it nicely, instead of throwing a
>>>> failure.
>>>
>>> the implicit bump sounds like a good idea (at least in theory?).
>>
>> Can you try current liburing -git? Remove your own RLIMIT_NOFILE and
>> just verify that it works. I pushed a change for it.
> 
> Sounds like it pretty easy can be a very unexpected behaviour. Do many
> libraries / etc. implicitly tinker with it?

Don't know if they do, but as long as we simply increase probably not a
huge problem, even if not the prettiest. I just wish we had done this
for the 2.1 release, to avoid people running into this for stable
backports. At least it's a fairly well known (and specific) error code
for this case.

-- 
Jens Axboe